After the Iowa caucuses, this week's podcast focuses on US politics. Tom Clark is joined by Jonathan Freedland, Martin Kettle and Suzanne Goldenberg to assess the state of the race to clinch the Republican nomination for president.

The contest is in disarray after the frontrunner Mitt Romney beat Christian fundamentalist Rick Santorum by just eight votes. But how much momentum does Santorum have going into next week's New Hampshire primary contest?